The present invention relates to a multiplexer, a demultiplexer and to multiplexing-demultiplexing equipment with configurable frames.
The digitization of transmission networks requires the use of digital multiplexing-demultiplexing equipment ensuring the regrouping of a certain number of basic information channels in a single transmission channel with a higher flow rate. The diversity of multiplexing equipment continues to increase bearing in mind the large number of standardized basic flow rates or those which are in the process of being standardized (data, word coding, picture coding, etc.), the different standardized hierarchic levels with European and American standards and finally different types of existing multiplexing, such as synchronous multiplexing, multiplexing with positive justification or multiplexing with positive-negative justification.
The realisation of multiplexing equipment usually requires the definition and development of a certain number of specific high integration components which cannot generally be advantageously used in other equipment of the same technology. This leads to a large amount of research on components and consequently high purchasing and maintenance costs, particularly for equipment produced in small quantities.
Moreover, in view of the ever-increasing complexity of telecommunications networks, it becomes vital during the research carried out on multiplexing equipment to have elaborate operating functions, a constant monitoring of the transmission quality and a precise and effective location of defective parts in the multiplexing equipment. These operating functions are generally realised with the aid of microprocessor circuits. This only utilizes a very small part of the technical possibilities of microprocessor circuits and generally leads to high costs compared with the function performed.
Reference can be made to the work "Transport et traitement de l'information dans les reseaux et systemes teleinformatiques", DUNOD, 1979, C. C. MACCHI and J. F. GUILBERT and more particularly pp. 115 to 141 for a description of multiplexers and pp. 371 to 375 for a description of intelligent multiplexers called concentrators.